In many applications, such as, aeronautical, guidance, ballistic, as well as others, it may be desirable to have inertial measurement units (IMU) having sensor suites, such as an inertial sensor assembly (ISA), that can detect acceleration and rotation in three planes. To provide the measurements in three planes, at least one sensor is often mounted orthogonal to a PWB that carries the other sensors. To accomplish this, and in some cases, a ceramic block is provided that includes a bottom wall and a sidewall that extends up generally perpendicular to the bottom wall. The bottom wall often includes bond pads that are bonded to bond pads on a PWB. Likewise, the side wall often includes bond pads, and a sensor is mounted to the bond pads on the side wall so that the sensor is generally orthogonally mounted relative to the PWB. Traces are often provided along the outside surface of the ceramic block between the bond pads on the bottom wall and the bond pads on the side wall to make the desired electrical connections between the orthogonally mounted sensor and the PWB. The other sensors of the ISA may be mounted directly to the PWB.
It has been found that such conventional ceramic blocks may not be able to withstand the relatively high acceleration forces associated with some high dynamic environments, such as some aeronautical, guidance, and ballistic environments. In addition, little shielding is provided on the traces that travel along the outer surface of the ceramic block, which in some cases, can result in performance limiting noise particularly for some sensitive sensor signals. Also, conventional ceramic blocks can be relatively expensive to manufacture.